The present disclosure provides a display device, and an image data processing apparatus and method. The image data processing apparatus is applied in a pixel matrix, and includes: an edge detecting module, configured to receive to-be-displayed image data in the pixel matrix, and perform edge detection on the to-be-displayed image data to acquire edge pixels located at an edge of a predetermined type; a subpixel selecting module, configured to judge whether the first and second subpixels in the edge pixels are located on an even more outer side at the edge of the predetermined type relative to the third subpixel, and select the first and second subpixels located on the even more outer side at the edge of the predetermined type relative to the third subpixel as to-be-adjusted subpixels; a luminance attenuating module, configured to perform luminance attenuation on the to-be-adjusted subpixels; and a data transmitting module.